JP2022171230A - Wind power generation windmill - Google Patents

Abstract

To prevent a lightning strike by suppressing generation of an upward streamer around a wind power generation windmill via lightning suppression means, and to secure the health of the windmill by preventing detachment of the lightning suppression means from a blade.SOLUTION: Lightning suppression means 7 is arranged at a tip of a blade constituting a windmill main body 2. The lightning suppression means comprises a first electrode 9 which is formed in a substantially spherical shell shape having an internal space B, a second electrode 10 arranged in an internal space at an interval from the first electrode, and an electric insulator interposed between the first electrode and the second electrode. An opening 9a that provides communication from the internal space communicate with the outside is formed in a part of a shell wall of the first electrode, with a protruding connection cylinder 12 going outward from an edge part of the opening being provided. One end of a connecting rod 13 inserted into the connecting cylinder and the opening is anchored to the second electrode. The electric insulator is arranged covering inside and outside faces of the connecting cylinder and the connecting rod, and is fixed to the connecting rod together with the connecting cylinder by a fixing member. The connecting rod is electrically connected to a ground line 8.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a wind turbine for wind power generation, and more particularly to a wind turbine for wind power generation that suppresses lightning strikes on blades constituting the wind turbine for wind power generation to suppress damage to the blades.

Generally, wind power generation energy is known as one of renewable energy.
The wind turbine for wind power generation that generates this wind power generation energy includes a high column, a nacelle mounted on the top of the column and containing a generator, and a number of blades mounted on the nacelle for rotating the generator. It is composed of

In this wind turbine for wind power generation, when the blades are rotated by the wind, the rotation of the blades drives the generator to generate electricity.

In such a wind turbine for wind power generation, in order to receive the wind efficiently, the columns are raised and the installation positions of the blades are raised.
Also, the blades are made long and large in order to increase the amount of power generation.

By the way, lightning strikes are likely to occur in such a wind turbine for wind power generation that is installed to extend to a high place.
When lightning strikes the blades, the blades and the nacelle are damaged by the lightning strike, making it impossible to generate electricity.

Conventionally, a coping technique as disclosed in Patent Document 1, for example, has been proposed for such a problem.

This technique has a configuration in which a metal lightning receiver is provided at the tip of the blade, a ground wire is electrically connected to the power receiver, and the ground wire is buried in the ground through the inside of the blade.

Then, when a lightning strike toward the wind turbine for wind power generation occurs, the lightning strike is guided to the lightning receiving section and received, and the lightning strike is flowed from the lightning receiving section to the ground via the ground wire, The lightning strike is prevented from passing through the blades and nacelle to prevent damage to the blades and nacelle.

JP 2012-246812 A

By the way, the conventional technique described above still has the following problems to be solved.

In other words, when the blade stops rotating, the lightning receptor is in a fixed position.
In this state, if a lightning strike occurs toward the blade, the lightning strike can be guided and received by the lightning receiver located at a fixed position, and the lightning strike can be discharged to the ground through the ground wire.

However, when the blade is rotating, the linear velocity of the tip, that is, the movement speed of the lightning receptor is high, so it is assumed that the lightning strike directed to the blade cannot be guided to the lightning receptor. be done.

In this way, if the lightning strike directed toward the blade cannot be guided to the lightning receiving portion, the lightning strike occurs at a portion of the blade other than the lightning receiving portion, and the lightning strike passes through the blade itself. , is discharged to the ground through the nacelle and struts.

It is assumed that the blades and nacelle may be damaged by lightning strikes passing through the blades, nacelle, and struts.

Such problems are based on the idea of guiding lightning strikes to places other than unprotected objects such as important facilities or equipment, thereby protecting the aforementioned unprotected objects from lightning strikes that occur when lightning strikes. This is due to the existence of

On the other hand, in addition to the above-described method of inducing lightning strikes to a place other than the object to be protected and protecting the object to be protected from lightning strikes, a lightning strike suppressing means for generating a negative charge equal to the negative charge that is charged at the bottom of the thundercloud is used. A method of attaching it to the tip of the to confront the thundercloud has also been proposed.

In this method, the negative charge of the blade and the negative charge of the lower part of the thundercloud are opposed to each other, thereby eliminating the induction phenomenon itself of the lightning strike and suppressing the lightning strike.

However, even when such a lightning strike suppression means is used, the following problem remains to be solved.

The lightning strike suppressing means is attached to the tip of the blade, and centrifugal force acts on the lightning strike suppressing means as the blade rotates.
This centrifugal force acts to separate the lightning strike suppression means from the blade as the blade rotates faster and as the length of the blade increases. Therefore, countermeasures are required.

An object of the present invention is to provide a wind turbine for wind power generation that can prevent such a lightning strike suppression means from being detached as much as possible.

A wind turbine for wind power generation according to the present invention is configured as follows in order to solve the above-described problems.
A lightning strike suppression means is provided at the tip of a blade that constitutes the wind turbine main body, and the lightning strike suppression means includes a first electrode formed in a substantially spherical shell shape having an internal space, and a space between the first electrode and the first electrode in the internal space. and an electrical insulator interposed between the first electrode and the second electrode, wherein a part of the shell wall of the first electrode defines the internal space. An opening communicating with the outside is formed, and a connecting tube projecting outward from the edge of the opening is provided, and the second electrode is connected through the connecting tube and the opening. One end of the rod is fixed, and the electrical insulator is provided covering the inner and outer surfaces of the connecting tube and the connecting rod, and a fixing member made of an electrically insulating material attaches the connecting tube to the connecting rod together with the connecting tube. The other end of this connecting rod is electrically connected to a grounded ground wire.

Here, when observing the phenomenon of lightning strikes in detail, in the case of general lightning strikes that occur in the summer (summer lightning), when the thundercloud matures, the stepleaders from the thundercloud approach the ground while choosing a place where the atmosphere is easy to discharge.
When the step leader reaches a certain distance from the ground, an upward streamer of weak current (welcoming discharge) extends from the ground, building (lightning rod), tree, etc. toward the step leader.
When this streamer and step leader are coupled, a large current (return current) flows between the thundercloud and the ground through the path. This is the phenomenon of lightning strikes.

In the present invention, with the configuration described above, the first electrode and the second electrode are opposed to each other in an electrically insulated state by the insulator.
This causes the second electrode electrically connected to ground to have the same charge as the ground, and the first electrode covering the second electrode to have the opposite charge.

Therefore, when a thundercloud with a negative charge distributed on the cloud base approaches, the opposite charge (positive charge) is distributed on the surface of the ground, and the second electrode electrically connected to this ground is also charged with a positive charge. , the first electrode, which is arranged through an insulator, is negatively charged by the action of the capacitor.

The rotation of the windmill causes the first electrode to face the thundercloud, but since these are charged with the same negative charge, upward streamers from the blades toward the thundercloud are less likely to occur. can be suppressed.

Such a lightning strike suppression effect is expected to extend not only to wind turbines but also to power supply and distribution facilities installed alongside wind turbines.

On the other hand, the electric insulator is provided covering the inner and outer surfaces of the connecting cylinder and the connecting rod, and is fixed to the connecting rod together with the connecting cylinder by a fixing member made of an electrically insulating material. The electrode and the second electrode are rigidly connected to the connecting rod.

Here, centrifugal force acts on the lightning suppression means due to the rotation of the windmill. It is possible to prevent the suppressing means from being detached from the blades and ensure the soundness of the wind turbine.

It is preferable that the lightning strike suppressing means is mounted so that the tip of the blade is positioned at the base of the connecting tube of the first electrode.

With such a configuration, the blade-side surface of the first electrode can be exposed toward the rear of the blade.

Thus, when the windmill is rotated and the lightning strike suppression means is positioned downward, the side surface of the blade of the first electrode can be exposed upward to face the thundercloud.

As a result, when the lightning strike suppressing means moves around the rotation axis of the windmill as the windmill rotates, the first electrode can always face the thundercloud to enhance the lightning protection effect.

The first electrode has a circular or elliptical cross section.
In particular, in the case of an elliptical shape, it is possible to smoothly connect the shape of the tip of the blade and the shape of the lightning strike suppressing means by attaching the blade to the blade so that the major axis of the elliptical shape extends along the length of the blade. .

Ceramics are preferably used for the electrical insulation.

According to the wind turbine for wind power generation of the present invention, the lightning suppression means can suppress the generation of upward streamers around the wind turbine for wind power generation to suppress the occurrence of lightning strikes, and the lightning suppression means can be prevented from being detached from the blades. to ensure the integrity of the wind turbine.

1 is a front view showing a wind turbine for wind power generation to which one embodiment of the present invention is applied; FIG. 1 is an enlarged vertical cross-sectional view of a main part of a blade of a wind turbine for wind power generation to which an embodiment of the present invention is applied; FIG. 1 is a front view of a wind turbine for wind power generation for explaining the action of one embodiment of the present invention; FIG. 1 is a front view of a wind turbine for wind power generation for explaining the action of one embodiment of the present invention; FIG. FIG. 4 is an enlarged vertical cross-sectional view of a main part of a blade of a wind turbine for wind power generation to which another embodiment of the present invention is applied;

An embodiment of the present invention will be described below with reference to the drawings.
In FIG. 1, reference numeral 1 denotes a wind turbine for wind power generation to which this embodiment is applied. A power supply and distribution facility 3 for supplying and distributing the electric energy generated in , and a power transmission line 4 are provided.

The wind turbine body 2 includes a column 5, a nacelle (not shown) provided at the upper end of the column 5, and a plurality of blades 6 attached to the nacelle. is provided with lightning strike suppressing means 7.

A grounding wire 8 is provided inside the column 5, one end of which is electrically connected to the lightning strike suppressing means 7, and the other end of which is buried in the ground A and grounded.

Each of the blades 6 is connected to a generator (not shown) mounted inside the nacelle, and the blades 6 are rotated by the wind to drive the generator and generate electricity. It is designed to perform

As shown in FIG. 2, the lightning strike suppressing means 7 includes a first electrode 9 formed in a substantially spherical shell shape having an internal space B, and arranged in the center of the internal space B with a gap from the first electrode 9. and an electrical insulator 11 interposed between the first electrode 9 and the second electrode 10 . A portion of the shell wall of the first electrode 9 is formed with an opening 9a that communicates the internal space B with the outside, and a connecting cylinder 12 protrudes outward from the edge of the opening 9a. ing. One end of a connecting rod 13 inserted through the connecting cylinder 12 and the opening 9a is fixed to the second electrode 10 . The electrical insulator 11 is provided to cover the inner and outer surfaces of the connecting tube 12 and the connecting rod 13, and is fixed to the connecting tube 12 and the connecting rod 13 by a fixing member 14 made of an electrically insulating material. The other end of this connecting rod 13 is electrically connected to a grounded ground wire 8 .

The first electrode 9 is made of a conductive material (for example, stainless steel) and formed into a spherical shell having a perfectly circular cross section, and is partially cut to form an opening 9a.

The connecting tube 12 extending outward is integrally connected to the edge of the opening 9a.

The second electrode 10 is a solid sphere made of a conductive material, and is fixed by a fixing bolt 15 to the insertion end of a connecting rod 13 inserted into the first electrode 9 .

In this embodiment, the connecting rod 13 is formed to have a length from the tip end to the base end of the blade 6, and a screw 13a is formed on the base end side.

A portion of the connecting rod 13 where the screw 13a is formed is passed through a locking plate 16 which is locked to a locking stepped portion 6a formed at the proximal end of the blade 6, and a fixing nut is inserted into this penetrating portion. 17 is screwed on.

The fixing nut 17 is pressed against the locking plate 16, and the blade 6 is sandwiched between the fixing nut 17 and the electrical insulator 11 fixed to the connecting rod 13 from the length direction. A first electrode 9 , a second electrode 10 and an electrical insulator 11 are adapted to be fixed to the blade 6 .

The electrical insulator 11 includes a first electrical insulator 11a that covers the tip of the connecting rod 13 and fills the gap between the connecting rod 13 and the connecting cylinder 12, and a lower peripheral surface and a lower surface of the first electrical insulator 11a. and a second electrical insulator 11b provided covering the .

A reinforcing ring 18 is interposed in the overlapping portion between the first electrical insulator 11 a and the connecting tube 12 .

Also, at the tip of the connecting rod 13, the portion where the tip of the first electrical insulator 11a is superimposed, the first electrical insulator 11a, the reinforcing ring 18, and the second electrical insulator 11b are superimposed. Annular grooves 19 and 20 are formed in the portions where the grooves are formed.

The fixing member 14 is made of an electrical insulating material, and is screwed through the first electrical insulator 11a and pressed into the annular groove 19 of the connecting rod 13. The reinforcement ring 18 and the first electrical insulator 11 a are threaded and pressed into the annular groove 20 of the connecting rod 13 .

As a result, the lightning strike suppression means 7 is fixed to the blade 6 in a state in which relative movement of the blade 6 in the longitudinal direction is restrained.

In this embodiment configured as described above, as shown in FIG. 1, when a thundercloud with negative charges distributed at the cloud base approaches, the opposite charges (positive charges) are distributed on the surface of the ground A, The second electrode 10, which is electrically connected via the ground line 8, is also positively charged.

On the other hand, the first electrode 9, which is connected to the second electrode 10 via the electrical insulator 11 and is spaced apart by the internal space B, takes on a negative charge due to the action of the capacitor.

As a result, as shown in FIG. 1, a negatively charged region is formed around the wind turbine body 2, and a thundercloud is opposed to this negatively charged region, but the bottom of this thundercloud is also negatively charged. Therefore, the occurrence of lightning strikes is suppressed by suppressing the generation of upward streamers directed from the blades 6 toward the thundercloud.

As shown in FIGS. 3 and 4, the effect of suppressing the generation of upward streamers is maintained whether the blade 6 is stopped or rotated.

Here, in the present embodiment, the first electrode 9 is spherical, and the tip of the blade 6 is located at the base of the connecting tube 12 of the first electrode 9. It can be exposed as much as possible.

As a result, even when the lightning strike suppressing means 7 is moved downward, the area of the first electrode 9 exposed upward can be increased, and the area of the negative charge that faces the thundercloud can be expanded. .

As a result, the effect of suppressing the generation of upward streamers can be enhanced to effectively suppress lightning strikes.

In this way, even when the blades 6 are in a stopped state or in a rotating state, the blades 6 and other constituent members of the wind turbine main body 2, or various facilities installed together with the wind turbine main body 2 lightning strikes can be suppressed.

On the other hand, the lightning strike suppressing means 7 is fixed to the annular grooves 19 and 20 of the connecting rod 13 by the fixing member 14, so that relative movement of the blade 6 in the longitudinal direction is strongly restrained.

Therefore, even if the wind turbine main body 2 is rotated and a large centrifugal force is applied to the lightning strike suppression means 7 , the lightning strike suppression means 7 will not separate from the blades 6 .

As a result, the soundness of the wind turbine main body 2 and, by extension, the soundness of the wind turbine 1 for wind power generation can be greatly improved.

FIG. 5 shows another embodiment of the invention.
In this embodiment, the first electrode 21 is modified to have an elliptical cross-section so that the length of the minor axis approaches the thickness of the blade 6 .

With such a configuration, the outer shape of the first electrode 21 can be brought closer to the outer shape of the blade 6, and the change in the overall shape of the blade 6 can be minimized.

It should be noted that the shapes and the like of the constituent members shown in each of the above-described embodiments are examples, and can be changed in various ways based on design requirements and the like.
For example, the first electrical insulator 11a and the second electrical insulator 11b may be screwed together. Furthermore, the first electrical insulator 11a and the second electrical insulator 11b and the blade 6 may be screwed.

1 Wind Turbine for Wind Power Generation 2 Wind Turbine Main Body 3 Power Supply and Distribution Facility 4 Power Transmission Line 5 Strut 6 Blade 6a Locking Step 7 Lightning Strike Suppression Means 8 Grounding Wire 9 First Electrode 9a Opening 10 Second Electrode 11 Electrical Insulator 11a First Electrical Insulator 11b Second electrical insulator 12 Connecting tube 13 Connecting rod 13a Screw 14 Fixing member 15 Fixing bolt 16 Locking plate 17 Fixing nut 18 Reinforcing ring 19 Circular groove 20 Circular groove 21 First electrode A Ground B Internal space

Claims (5)

A wind turbine for wind power generation in which a lightning strike suppressing means is provided at the tip of a blade constituting a wind turbine body,
The lightning strike suppression means includes a first electrode formed in a substantially spherical shell shape having an internal space, a second electrode arranged in the internal space with a gap from the first electrode, the first electrode and the an electrical insulator interposed between the second electrode,
An opening is formed in a part of the shell wall of the first electrode to communicate the internal space with the outside, and a connecting cylinder is projected outward from the edge of the opening,
One end of a connecting rod inserted through the connecting cylinder and the opening is fixed to the second electrode,
The electrical insulator is provided covering the inner and outer surfaces of the connecting cylinder and the connecting rod, and is fixed to the connecting rod together with the connecting cylinder by a fixing member made of an electrically insulating material,
A wind turbine for wind power generation, wherein the other end of the connecting rod is electrically connected to a grounded ground wire. 2. The wind turbine for wind power generation according to claim 1, wherein the tip of said blade is positioned at the base of said connecting tube of said first electrode. The wind turbine for wind power generation according to claim 1, wherein the cross-sectional shape of the first electrode is a perfect circle. 2. The wind turbine for wind power generation according to claim 1, wherein the first electrode has an elliptical cross-sectional shape and is attached to the blade so that the major axis of the first electrode extends along the length of the blade. . The wind turbine for wind power generation according to claim 1, wherein the electrical insulator is ceramics.

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